Weather - it’s all around us and it’s always changing.
This makes it a great resource for
gathering and organizing data
with graphs.
Graphs help us organize information and data in an understandable way. In today’s “New Times” we are surrounded by data, from sports statistics to politics to numbers presented in science textbooks.
Graphs “are the visual representations that focus on the relations between the ‘objects’ of representation in terms of a part-whole structure.”
Koulaidis (p.1998)
1. Collect and organize appropriate data
2. Represent the data graphically, by selecting the appropriate graph
3. Read and interpret graphs
4. Evaluate and analyze information presented in graphs that are found in textbooks, newspapers, digital media, etc. Look for intent behind the graphic representation of the data.
What are we trying to teach our students?
When students make graphs from data they collect, graph interpretation is easier and more interesting because it is based on actual experience with the numbers involved.
The experience of interpreting their own graphs gives students the skills to interpret graphs made by others.
Day
Outside
Temp (ºF)
Inside
Temp (ºF)
Difference
(Out minus In)
(ºF) Notes
1 80ºF 72ºF 8ºF sunny
2 71ºF 71ºF 0ºF cloudy & rain
3 86ºF 73ºF 13ºF windy
4 89ºF 70ºF 19ºF sunny
5 79ºF 69ºF 10ºF cloudy
6 95ºF 80ºF 15ºF broken a/c
• recording data,• computing the range of data (the difference between • two sets of data to give a sense of how “spread out” they are), and • finding the central tendency (mean) to get an idea of a typical value.
Children begin by
How do we help students decide which type of graph is best for the data?
In the same way that educators use concept maps or graphic organizers, chapter outlines, webbing, and structured overviews to help students navigate text, so can graphs and charts be used as tools to organize and present data.
• Circle map• Double bubble• Tree map• Flow map
Column Graph
0
10
20
30
40
50
60
70
80
90
100
1 2 3 4 5 6 7
Days
Tem
pera
ture
Series1
Series2
Bar Graph
0 20 40 60 80 100
1
2
3
4
5
6
7
Tem
pera
ture
Days
Series2
Series1
Area Graph
0
10
20
30
40
50
60
70
80
90
100
1 2 3 4 5 6 7
Days
Tem
pera
ture
Series1
Series2
Line Graph
0
10
20
30
40
50
60
70
80
90
100
1 2 3 4 5 6 7
Days
Tem
pera
ture
Series1
Series2
Line Graphs Pie Charts Bar Graphs Organizational Charts
Dealing with Data
•Key/legend (symbols)•Axes (X, Y and Z)•Gridlines•Scale•Data Labels•Data Table•2 Dimension•Variables and their relationships to each other
Vocabulary Needed for
Decoding Graphs
Does the scale make a difference in how you react to the data?
Do the graphs below show the same information? Do the pictures suggest the same idea?
Is one graph misleading?
Temperatures Plummet
78
80
82
84
86
88
90
92
94
96
1 2 3 4 5 6 7
Days
Tem
pera
ture
(ºF
)
Series1
Temperatures Stable
0
10
20
30
40
50
60
70
80
90
100
1 2 3 4 5 6 7
Days
Tem
pera
ture
(ºF
)
Series1
Does the line graph tell you anything about the temperatures in between the times the readings were taken?
Students were asked to guess
what part of the total amount of water on Earth
(unchanged since when the Earth
was formed) is in the oceans, ice, groundwater, atmosphere (clouds) and
lakes & rivers.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Where in the World is All the Water?
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
The students then graphed their predictions against the actual amounts, dramatically illustrating their misconceptions about Earth’s water sources.
Pie Charts
Where in the World is all the Water?
0
100
200
300
400
500
600
700
800
900
1000
1 2 3 4 5
Location of Water
mls
of
Wate
r
Series1
Series2
Distribution of Water in the World
1
2
3
4
5
1 = Oceans 2 = Ice water3 = Groundwater 4 =Atmospheric water 5 = Lakes & River
From simple
to…..
Back to temperature…
… complex!
Note: a example of nominalization used in the context of analyzing this type of data is “rate of change of temperature”
Clues that something is “fishy” about a graph:
1. The axis should begin with zero so that the measurement scale is shown whole.
2. If one of the axes is not labeled, you do not really know what is being displayed.
3. The numbers are identified by their units.
4. The X to Y axis scaling is not fair, i.e. one axis has been stretched out.
Proportion of Page comprised of Images versus Words
High Image.Low Word
High Image.Moderate
Word
Moderate Image.High Word
Low Image
HighImage
Low Word
High Word
ElementarySchool
MiddleSchool
HighSchool
Juggling 2 variables at once
What does this graph tell us?
Do you believe the data?
Who collected the data?Where and how were the temperatures taken?
Predicting the Future
• Human activities are changing the environment. Global temperatures have risen by 0.6 degrees Celsius in the last 200 years.
Does scale make a difference in this graph?
• This graph shows carbon dioxide emissions increasing the last 130 years.
What kind of impact does the image have on the reader?
Importance of titles and captions
Reader Beware!
1. Graphs have more impact than the raw data because they are visual.
2. Graphs represent interpretations of data. If the data has been specially selected, then the interpretation is only of the selected data.
3. Data can be plotted to create an impression of (or hide) a dramatic trend when in fact the data does not support such an apparent change.
4. The creator of the graph can influence the impact of the information and therefore influence the viewer.
“What is the social cost of “innumeracy” and illiteracy?
The inability to deal rationally with large numbers, or with the probabilities [and their graphic
Paulos (1988)
representations] associated with them, results in misinformed government policies, confused personal decisions, and an increased susceptibility to pseudo-sciences of all kinds.”
There “are cases where there is no dishonesty involved, but where people are tricked into false results by a lack of understanding about what human beings can do to themselves in the way of being led astray by subjective efforts, wishful thinking or threshold interactions.”
Cromer (1993)
Why do we care about visual literacy?
If our students do not understand and get meaning from visual information, they will be excluded, their point of view not considered, or they may even manipulated into believing
something not in their best interest.